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Finding the Fourth Proportional to 80.85, 120.83 and 67.35

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Solution

The fourth proportional to 80.85, 120.83 and 67.35 is: 100.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.85 : 120.83 = 67.35 : x
  2. Step 2: Convert to fraction form
    80.85/120.83 = 67.35/x
  3. Step 3: Cross multiply
    80.85x = 120.83 × 67.35
  4. Step 4: Simplify right side
    80.85x = 8,137.56
  5. Step 5: Solve for x
    x = 8,137.56/80.85
  6. Step 6: Final answer
    x = 100.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.